[baseh]

TLDR;

>This section through a young octopus shows the stripey-looking brain between the two advanced camera eyes, surrounding part of the oesophagus (small white centre towards the base of the eyes). Also visible are two of the characteristic arms, with multiple suckers and thick nerves running through them. The strange and seemingly precarious arrangement of the

[ethbro]

I believe the problem is that it's a section of a 3d ring structure wrapped around a cylinder without the accompanying text highlighting that fact.

[dingo_bat]

Is this correct? https://i.imgur.com/1tQcqAB.png

Sorry for being dumb :/

[zardo]

I think the top brain is the digestive system.

[BioSciCreative]

​Based on what appears to be pattern in the "top brain" I believe it to be some kind of secretion or filtering organ. Based on my reference links above in the reply to bluenose69, I think it is the digestive gland. The stomach is actually much smaller and has a hollow opening​ at the very "top" of the octopus​. ​

[dingo_bat]

Ah! Now it makes sense. Thanks!